The below excerpts are from the D&DI Compendium entry on "Short Rest", referencing PHB 1.

No Strenuous Activity: You have to
rest during a short rest. You can
stand guard, sit in place, ride on a
wagon or other vehicle, or do other
tasks that don’t require much
exertion.

Using Powers while You Rest: If you
use an encounter power (such as a
healing power) during a short rest,
you need another short rest to renew
it so that you can use it again.

It seems apparent that you can use powers during rest periods as well as other non-encounter situations. However, while the rule does specify that you cannot perform "strenuous activity", it doesn't seem to state whether power usage falls into that category.

If you do decide to use a power during your resting period, do you have to take another rest period to gain the benefits of a short rest, or do you just add more time to the same resting period?

Or, is this really a negligible issue, since most powers take only 6 seconds (1 combat round) to use?

3 Answers
3

The only powers that matter during a rest are encounter powers. Daily powers will not refresh. At-Will powers cannot deplete.

The rules specify what happens if you use an encounter power during a short rest (you need to rest again to refresh it), note that it does not say that your rest is invalidated.

Usage of non-encounter powers during a short rest do not in and of themselves negate the rest or increase the duration. Of course, the DM is free to rule that certain usages are strenuous activity.

To cross my personal line as a DM, a character would have to use more than a couple powers during a rest to have it become "strenuous" In no way would I allow someone to use 50 powers (or one power 50 times during a rest)!.

I'd adjudicate it based on the time restraints of the situation. In most cases, the difference between a 5 minute break and a 10 minute break aren't going to matter so I don't push the issue.
Sometimes it does matter though and in those cases it depends on when the power was used. If they ended the fight with the power unused, then I assume it was used right away and I don't add to the 5 minutes. I do this because if you don't, you're going to have players sand bagging killing the last baddie, so that they can make sure everyone has used the powers they want before resting (usually heals). If they are relying on powers to recharge during the rest, I make them rerest for 5 more. Afterall, they get encounter powers back at the end of the rest right?

I allow At-wills during rests because I assume they are easy enough to not cause "exertion".